WO2008023647A1

WO2008023647A1 - Base station and mobile station

Info

Publication number: WO2008023647A1
Application number: PCT/JP2007/066052
Authority: WO
Inventors: Yoshiaki Ofuji; Kenichi Higuchi; Mamoru Sawahashi
Original assignee: Ntt Docomo, Inc.
Priority date: 2006-08-22
Filing date: 2007-08-17
Publication date: 2008-02-28
Also published as: EP2056614A4; US20110149896A1; CN101529958A; JP4519817B2; RU2458475C1; US8018898B2; BRPI0722406A2; TWI348296B; BRPI0715372A2; EP2309814A1; KR20090042968A; RU2444862C2; US8000296B2; TW201134133A; KR101448014B1; US20100232374A1; RU2009108794A; KR20110025879A; TWI422183B; KR101252575B1

Abstract

A resource block in which a system bandwidth is divided into continuous frequency subcarrier blocks or a distributed resource block formed by frequency subcarriers discretely distributed in the system bandwidth and configured by dividing the resource block into a plurality of parts is allocated to each of mobile stations. A base station includes scheduling means for allocating one of the resource block and the distributed resource block to the mobile stations with a predetermined allocation cycle in accordance with the downlink reception channel state reported from the mobile station.

Description

Specification

Base station and mobile station

Technical field

[0001] The present invention relates to an LTE (Long Term Evolution) system, and more particularly to a base station and a mobile station.

Background art

[0002] A resource block (RB:

High-speed packet scheduling that assigns transmissions to users based on the reception channel state for each (Resource Block) can achieve high frequency utilization efficiency.

However, in order to realize high-speed packet scheduling, from the base station to each user terminal

In addition, it is necessary to notify the allocation information for each transmission slot or each resource block, and it is necessary to feed back the propagation path state from each user terminal to the base station.

Non-Patent Document 1: Ericsson, R1— 060099, “Persistent Scheduling for E— UTRA”, TSG-RAN WG1 LTE AdHoc, Helsinki, Finland, Januar y 23— 25, 2006

Disclosure of the invention

Problems to be solved by the invention

[0004] The above-described high-speed packet scheduling is difficult to apply to traffic in which packets of a substantially fixed size are generated at a constant cycle and the requirements for delay are severe, such as voice services. This is because for such traffic, for example, even if transmission data is generated when the reception state is bad, it is not allowed to wait until the reception state is improved. Therefore, for such traffic, there is a request for allocating radio resources fixedly at regular intervals without considering the reception state.

[0005] Therefore, persistent scheduling has been proposed in which predetermined radio resources are periodically allocated to traffic such as VoIP in which data is periodically generated (for example, Non-patent document 1). [0006] However, this proposal is based on a concept, and has been proposed for a specific base station and mobile station configuration! /!

Therefore, an object of the present invention is to provide a base station and a mobile station that can periodically allocate predetermined radio resources to traffic in which data is periodically generated.

Means for solving the problem

[0008] In order to solve the above problems, a base station of the present invention includes:

A distributed resource block comprising a resource block in which the system bandwidth is divided into continuous frequency subcarrier blocks and frequency subcarriers that are discretely distributed within the system bandwidth, and the resource block is divided into a plurality of blocks. Assign one of these to each mobile station,

Scheduling means for allocating one of a resource block and a distributed resource block to the mobile station at a predetermined allocation period determined in advance based on a downlink reception channel state notified from the mobile station ;

One of the features is to have

With this configuration, radio resources can be fixedly allocated to mobile stations at a constant cycle.

[0010] Another base station of the present invention,

Pilot channel transmission band allocating means for allocating the transmission band of the pilot channel for measuring the uplink reception channel state with a period longer than the data channel allocation period;

A data channel transmission band allocating means for allocating, as a data channel transmission band, a resource block obtained by dividing the system bandwidth into continuous frequency subcarrier blocks to each mobile station;

Control information generating means for generating a control signal for notifying each mobile station of the transmission bandwidth of the pilot channel and the transmission bandwidth of the data channel that have been determined to be allocated;

The data channel transmission band allocating means determines the pilot channel reception quality. One of the characteristics is to determine the allocation of the transmission bandwidth of the data channel based on

With this configuration, it is possible to allocate the pilot channel transmission band for measuring the uplink reception channel state with a period longer than the data channel allocation period. Based on the reception quality, it is possible to determine the allocation of the data channel transmission band to each mobile station.

[0012] The mobile station of the present invention

Pilot signal generating means for generating the pilot channel with a period longer than the data channel allocation period for the base station using the frequency band allocated by the base station;

Transmission data allocating means for allocating transmission data at a predetermined allocation cycle determined in advance to the resource block allocated to the base station based on the pilot channel! /;

A mobile station comprising:

With this configuration, the pilot channel is generated with a period longer than the data channel allocation period for the base station using the frequency band allocated by the base station, In the base station, transmission data can be allocated to a resource block allocated based on the pilot channel at a predetermined allocation period determined in advance.

The invention's effect

[0014] According to the embodiments of the present invention, it is possible to realize a base station and a mobile station that can periodically allocate predetermined radio resources to traffic in which data is periodically generated.

Brief Description of Drawings

FIG. 1 is an explanatory diagram showing a transmission method in the downlink according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a transmission method in the uplink according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a transmission method in the downlink according to one embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a transmission method in the uplink according to one embodiment of the present invention. FIG. 5 is an explanatory diagram showing the release of resource blocks in the downlink, which is an embodiment of the present invention.

FIG. 6A is an explanatory diagram showing the release of resource blocks in the uplink, which is an embodiment of the present invention.

FIG. 6B is an explanatory diagram showing the release of resource blocks in the uplink, according to one embodiment of the present invention.

FIG. 6C is an explanatory diagram showing the release of resource blocks in the uplink according to one embodiment of the present invention.

FIG. 7A is an explanatory diagram showing data transmission and control information transmission timing according to one embodiment of the present invention.

FIG. 7B is an explanatory diagram showing data transmission and control information transmission timing according to one embodiment of the present invention.

FIG. 8 is a partial block diagram showing a base station according to one embodiment of the present invention.

[Fig. 9] Fig. 9 is a partial block diagram showing a mobile station which is effective in one embodiment of the present invention.

FIG. 10 is a partial block diagram showing a base station according to one embodiment of the present invention.

[Fig. 11] Fig. 11 is a partial block diagram showing a mobile station which is effective in one embodiment of the present invention.

Explanation of symbols

[0016] 100 base station

200 mobile stations

BEST MODE FOR CARRYING OUT THE INVENTION

Next, the best mode for carrying out the present invention will be described based on the following embodiments with reference to the drawings.

In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

[0018] A mobile communication system that is advantageous in the present embodiment includes a base station 100 and a mobile station 200. Base station 100 and mobile station 200 periodically allocate predetermined radio resources to mobile station 200 and base station 100 for traffic in which data is periodically generated.

[0019] As described above, the base station 100 moves based on the frequency selectivity of the reception channel state. High-speed packet scheduling in the frequency domain that allocates resource blocks to the mobile station 200 increases L1 / L2 control signaling such as notification of allocation information of each resource block in the mobile station 200 and feedback of the reception channel state in the mobile station 200. .

[0020] Since the main purpose of persistent scheduling is to reduce L1 / L2 control signaling, the persistent scheduling applied to the mobile communication system, which is effective in this embodiment, is expected to have a frequency diversity effect. The following transmission methods are applied. As described above, persistent scheduling is a scheduling method in which predetermined radio resources are periodically allocated to traffic in which data is periodically generated.

[0021] For the downlink, OFDMA (Orthogonal Frequency Division Multiple

Access) is applied. OFDMA is a system that divides a frequency band into multiple narrow frequency bands (subcarriers) and transmits data on each frequency band. The subcarriers interfere with each other even though they overlap in frequency. By arranging them closely, it is possible to realize high-speed transmission and increase frequency utilization efficiency.

[0022] Further, in the downlink, a resource block level distributed transmission method for performing block division is performed. That is, as shown in FIG. 1, resource blocks that are made up of frequency subcarriers that are discretely distributed within the system bandwidth and that divide the system bandwidth into consecutive frequency subcarrier blocks are divided into a plurality of blocks (block division). Allocate distributed resource blocks configured to each user. Distributed resource blocks are allocated in a single transmission slot. A distributed resource block is assigned with a resource block level, that is, a resource block as a unit. Also, in the downlink, resource blocks obtained by dividing the system bandwidth that is not the distributed resource block described above into continuous frequency subcarrier blocks may be allocated to each user.

FIG. 1 shows an example in which a resource block is composed of two distributed resource blocks. The same distributed resource block may be allocated in a predetermined allocation cycle, or the distributed resource block allocated in each allocation cycle may be changed. By changing the distributed resource block allocated for each allocation period, A wave number diversity gain can be obtained. Here, the allocation cycle is a cycle in which distributed resource blocks are allocated to users, and depends on the type of data to be transmitted. For example, in the case of VoIP (Voice over Internet Protocol), it is 20 ms, which is the same as the packet transmission interval. Become.

[0024] By applying such a transmission method, in the downlink, adaptive modulation channel coding (AMC: adaptive modulation) that adaptively changes the modulation scheme and error correction coding rate according to changes in the propagation environment. mobile station 200 only feeds back the reception channel state averaged in the frequency domain, when (and coding) is applied. As a result, the base station 100 performs transmission so as to obtain a frequency diversity effect based only on the time variation of the reception channel state averaged over the entire band.

[0025] For the uplink, SC-FDMA (Single-Carrier Frequency Division Multiple Access) is applied. SC-FDMA is a transmission method that can reduce interference between terminals by dividing the frequency band and transmitting using different frequency bands among multiple terminals.

Further, in the uplink, as shown in FIG. 2, a localized transmission method using frequency hopping is performed. In other words, the resource block power obtained by dividing the system bandwidth into continuous frequency subcarrier blocks is allocated to the mobile station at a predetermined allocation period, and frequency hopping is applied to obtain a frequency diversity effect. Here, frequency hopping refers to switching resource blocks to be assigned for each transmission slot. Here, the allocation cycle is a cycle in which resource blocks are allocated to users, and depends on the type of data to be transmitted. For example, in the case of VoIP, it is 20 ms, which is the same as the packet transmission interval.

[0027] Next, a transmission method for obtaining the time diversity effect will be described.

[0028] When hybrid ARQ (hybrid automatic repeat request) combined with retransmission control (ARQ) and error correction coding processing is applied, signaling overhead is required because HARw is 7th signing. Will increase.

[0029] For example, when asynchronous HARQ is applied, dynamic allocation of transmission slots or resource blocks is required for retransmission, and notification of allocation information and retransmission are requested. Signaling to notify ACK / NACK is required. Asynchronous HARQ is a method of allocating retransmission opportunities at a certain time after the initial transmission timing, for example, at an arbitrary timing at least a certain time after Ack / Nack transmission on the receiving side.

[0030] Also, for example, when synchronous HARQ is applied, since allocation for retransmission is fixed, signaling of allocation information is not required. Signaling of AC K / NACK to request retransmission is necessary. . Here, synchronous HARQ is a method of assigning a retransmission opportunity after a certain time from the timing of initial transmission, for example, at least after a certain time from the Ack / Nack transmission on the receiving side.

[0031] Therefore, in the mobile communication system which is effective in the present embodiment, HARQ is not applied, and a predetermined number of times of transmission is performed in order to use the time diversity effect.

[0032] In this case, the same data may be transmitted twice, or the data sequence after channel coding may be mapped over a plurality of subframes.

FIG. 3 shows a transmission method in the case of downlink. Here, the data sequence after channel coding is mapped across a plurality of, for example, two subframes. In other words, the encoded data sequence is transmitted in two subframes. In this case, each of the two transmissions uses a plurality of, for example, two distributed resource blocks. Therefore, one encoded data sequence is divided into four parts and assigned.

[0034] By transmitting the encoded data sequence in two subframes, a time diversity effect can be obtained and reception errors can be reduced. There is a problem that decoding is not possible until it is received twice. However, if the allocation period is 20 ms and the transmission interval of the same data is 10 ms, the delay is about 10 ms, which is acceptable.

FIG. 4 shows a transmission method in the case of uplink. Again, the data sequence after channel coding is mapped across a plurality of, for example, two subframes. In other words, the encoded data sequence is transmitted in two subframes. By transmitting the encoded data sequence in two subframes, the time diversity effect can be obtained and reception errors can be reduced. There is a problem that decoding is not possible until it is received twice, but the assignment cycle is 20 ms and the same data transmission interval is 10 ms. The delay is about 10ms, which is acceptable.

[0036] In addition, in the mobile communication system that focuses on this embodiment, in order to satisfy a required packet error rate (PER), adaptive modulation channel coding and transmission power control (TPC) Control) is fi.

[0037] By applying adaptive modulation channel coding, the MCS (Modulation and Coding Scheme) to be used, that is, the base station 100 determines, for each mobile station 200, the received quality measured by each mobile station 200, etc. If the combination of the transmission data modulation scheme and the error correction coding rate determined in (2) changes, the required radio resources, for example, the number of distributed resource blocks change at the same time. However, it is not necessary to change the resource block allocation by using transmission power control together! /.

[0038] For example, long-period adaptive modulation channel coding control, for example, combining a transmission power control for each allocation period with a period of an allocation period or more, for example, a period of several hundreds ms or more. In this case, since the frequency of adaptive modulation channel coding and resource block allocation change is small, the upper layer signaling is used for notification of the change. This signaling occurs when the receiving state changes. In addition, L1 / L2 control signaling may be used in the same manner as signaling for users other than the user to be subject to persistent scheduling. When this L1 / L2 control signaling is used, it is necessary to secure radio resources in advance.

[0039] Further, in the mobile communication system that focuses on the present embodiment, persistent scheduling is also applied to the mobile station 200.

[0040] In this case, feedback of the reception channel state from base station 100 to mobile station 200, that is, information (downlink) indicating the transmission bandwidth of the pilot channel for measurement of the reception channel state for which allocation has been determined, mobile station The pilot signal transmission (uplink) cycle for receiving channel state measurement from 200 to base station 100 shall be equal to or greater than the assigned cycle. Specifically, the period is longer than the data channel allocation period.

[0041] In the downlink persistent scheduling, the feedback information of the reception channel state is notified using the following transmission method. That is, the base station 100 is based on the feedback information of the reception channel state from the mobile station 200! G Perform scheduling. The mobile station 200 feeds back the average reception state of the reception band using the uplink at a fixed period. The period is longer than the actual data channel assignment period.

[0042] The mobile station 200 transmits the reception channel state using a random access channel (RACH). In other words, it is transmitted by upper layer (L3) signaling. In addition, the mobile station 200 may transmit using a radio resource that is periodically assigned in advance and determined by time and frequency. In this case, the radio resource used for transmission is specified and notified at the start of communication using persistent scheduling. This radio resource is redesignated when the MCS is switched.

[0043] The reception channel state measurement signal in the uplink persistent scheduling is performed by the following transmission method. That is, the mobile station 200 transmits an uplink reception channel state measurement pilot signal to the base station 100, and the base station 100 uses the uplink received channel state measurement neuron signal to which the mobile station 200 power is also transmitted. Then measure the uplink reception status.

[0044] The base station 100 uses the distributed transmission described above for the uplink reception state to transmit information indicating the transmission bandwidth of the data channel to the distributed resource block, that is, the bandwidth of the frequency bandwidth for performing frequency scheduling. Transmit with a transmission bandwidth equal to. In addition, transmission may be performed in the allocated band by localized transmission. Here, the localized transmission is a transmission method in which a resource block obtained by dividing a system bandwidth into continuous frequency subcarrier blocks is assigned to each user. In this case, if it is necessary to transmit in a wide band far from the base station 100, the localize transmission may be performed multiple times, that is, divided into two or more times. That is, two or more transmission slots are allocated and transmitted.

[0045] Next, resource block release in persistent scheduling in the downlink will be described.

[0046] As shown in FIG. 5, base station 100 transmits the resource block or distributed resource block allocated by persistent scheduling to the user. If there is no data, release it and assign it to another user. That is, the base station 100 allocates a resource block or distributed frequency block when there is transmission data for the target user, and releases the resource block or distributed frequency block that was scheduled to be allocated when there is no transmission data. And assign it to other users.

[0047] The data transmitted from base station 100 includes a CRC on which a UE-ID is superimposed. The mobile station 200 detects a CRC in which UE-ID is superimposed on transmission data. Therefore, when resource blocks or distributed resource blocks are allocated to other users, the UE ID that is superimposed on the CRC is different, so an error is detected by CRC check. For this reason, the mobile station 200 can know whether or not the data is for its own station. Here, when retransmission control is performed, the user terminal (mobile station 200) transmits NACK as a retransmission request, but the base station 100 ignores this.

[0048] Next, release of resource blocks in persistent scheduling in the uplink will be described.

[0049] In the uplink, unlike the downlink described above, the mobile station 200 notifies the base station 100 of the presence or absence of transmission data in order to release the resource blocks allocated by persistent scheduling.

[0050] There are the following three methods for notifying the base station 100 of the presence or absence of transmission data.

[0051] As shown in FIG. 6A, when there is transmission data, the base station 100 is notified (Assign request base). For example, when there is transmission data in a predetermined cycle, for example, an allocation cycle, an allocation request for requesting allocation of resource blocks is transmitted.

[0052] Also, as shown in FIG. 6B, the base station 100 is notified when there is no transmission data (Release request base). For example, in a predetermined cycle, for example, an allocation cycle, when the transmission data is V, a release request for requesting release of the resource block is transmitted.

[0053] As shown in FIG. 6C, when the transmission data is generated and when the transmission data is lost, the base station 100 is contacted (Combination of assign and release request). For example, when there is transmission data in a predetermined cycle, for example, the allocation cycle, an allocation request is sent to request that a resource block be assigned to a harmful IJ. Send a release request to release the resource block.

[0054] This notification signal is transmitted by RACH. In other words, it is transmitted by upper layer (L3) signaling. In addition, transmission may be performed using a radio resource that is allocated in advance and determined by time and frequency. In this case, by allocating exclusive radio resources, users can be orthogonalized and the reception quality can be improved. Alternatively, multiplexing may be performed by a code division multiple access method with a small number of users who allocate radio resources that are fixedly allocated in advance.

[0055] Next, allocation timing of data transmission and control information transmission will be described.

[0056] When considering a voice service, it is conceivable to perform fixed radio resource allocation in the uplink and downlink (hereinafter referred to as uplink and downlink). In such cases, control information can be efficiently communicated by optimizing the timing of fixed radio resource allocation in the uplink and downlink, including radio resource allocation for control information transmission. This is possible.

[0057] The downlink reception channel state, presence / absence of uplink transmission data, and radio resources for transmitting an ACK / NACK for downlink data transmission are allocated immediately before downlink transmission. In this way, the downlink reception channel state can be reflected in the downlink adaptation of the downlink transmission. Also, by notifying the presence / absence of uplink data, free uplink radio resources can be reassigned to other users. In this case, the result of reallocation is notified simultaneously with the downlink data transmission.

[0058] Radio resources for uplink data transmission are allocated after downlink data transmission. In this way, when the radio resources for uplink data transmission are released, it is possible to notify the allocated user of the reallocation result. An ACK / NACK for downlink data transmission may be transmitted together with uplink data transmission.

[0059] Specifically, allocation timing of data transmission and control information transmission will be described with reference to FIG. 7A and FIG. 7B.

[0060] A case where uplink data is generated will be described.

[0061] The user terminal (mobile station 200) receives at least one of feedback of downlink reception channel state, allocation request or release request, and ACK / NACK for downlink data transmission. The above is transmitted (step S702). Here, since uplink data is generated, an allocation request is transmitted.

[0062] Next, the base station 100 performs link adaptation, that is, adaptive modulation channel coding based on the downlink reception channel state notified in the uplink, and based on the result of the link adaptation, Transmits downlink data. Also, when a release request is transmitted from the user terminal, the base station 100 transmits mapping information in a subframe of downlink data for users other than the user to which persistent scheduling is applied. Also, the base station 100 notifies uplink transmission allocation information. When a user's resource to which persistent tent scheduling is applied is released, a user other than the user to which persistent scheduling is applied to that resource

[0063] Next, the user terminal transmits uplink data. Here, you may send ACK / NACK for downlink data transmission at the same time! / ヽ (step S706).

Next, base station 100 transmits ACK / NACK for downlink data transmission (step S 706).

[0065] A case where downlink data is generated will be described.

[0066] When downlink data is generated, the above-described processing of step S702 and step S704 is negated.

[0067] That is, the user terminal (mobile station 200) transmits one or more of feedback of a downlink reception channel state and an allocation request or a release request (step S702).

[0068] Next, the base station 100 performs link adaptation based on the downlink reception channel state notified in the uplink, and based on the link adaptation result, the downlink data is transmitted. Send.

[0069] Also, base station 100 transmits mapping information in a subframe of downlink data for users other than users to which persistent scheduling is applied. Also

The base station 100 notifies uplink transmission allocation information. When a user's resource to which persistent scheduling is applied is released, a user other than the user to which persistent scheduling is applied is assigned to the resource (scheduled) Step S 704).

Next, the configurations of base station 100 and mobile station 200 that implement the mobile communication system described above will be described. Here, the functions of both the base station 100 and mobile station 200 to which persistent scheduling is applied in the downlink and the base station 100 and mobile station 200 to which persistent scheduling is applied in the uplink are described. The base station 100 and the mobile station 200 may be configured to include

[0071] The base station 100 and the mobile station 200 to which persistent scheduling is applied in the downlink will be described with reference to FIG. 8 and FIG.

[0072] The base station 100 includes an RF receiving circuit 102, a demodulation / decoding unit 104 connected to the RF receiving circuit 102, a scheduler 106 connected to the demodulation 'decoding unit 104, a scheduler 106, and a demodulation' decoding unit Determining the preferentially allocated resource block connected to 104 ・ Management unit 108, header information acquisition unit 110, packet selection unit 114 connected to header information acquisition unit 110, header information acquisition unit 110, packet A buffer management unit 112 connected to the selection unit 114 and the scheduler 106, a PDU (Protocol Data Unit) generation unit 116 connected to the packet selection unit 114, a transmission buffer connected to the PDU generation unit 116 and the buffer management unit 112 118, selector 120 connected to transmission buffer 118 and scheduler 106, one or a plurality of encoding 'coding as modulation processing means' modulator 122 connected to selector 120, and encoding' modulation unit 122 Connected An RF transmission unit 124 as a transmission power control means, and a control signal generation unit 126 connected to the RF transmission unit 124 and the scheduler 106.

A control signal including control information from each mobile station 200 is received by the RF receiving circuit 102, and the received control signal is input to the demodulation / decoding unit 104. Demodulation 'Decoding section 104 performs control signal demodulation' decoding processing, and performs uplink control information (downlink reception channel state for each resource block) of each mobile station 200, for example, for each resource block of each user terminal. Link CQI (Channel Quality Indicator) notification is sent to the scheduler 106.

[0074] Also, when the mobile station 200 feeds back a reception channel state by upper layer signaling, the upper layer control signal is input to the priority allocation resource block determination-management unit 108. . Determination of priority allocation resource block Based on the control signal of the higher layer, the resource block to be preferentially assigned is determined and input to the scheduler.

[0075] On the other hand, when an IP packet transmitted from the network is received, the header information acquisition unit 110 acquires packet header information such as a destination address from the received IP packet, and uses the acquired packet header information. The buffer management unit 112 is notified, and the IP packet is input to the packet sorting unit 114.

[0076] Based on the notified packet header information and the status of each queue notified from the transmission buffer 118, which will be described later, the nota management unit 112 designates the packet data storage destination for the packet selection unit 114. To do. Further, the nota management unit 112 inputs the destination address and the memory address of the queue corresponding to the address to the transmission buffer 118. Further, the buffer management unit 112 notifies the scheduler 106 of the status of each queue notified from the packet header information and the transmission buffer 118.

The packet sorting unit 114 sorts the input IP packet based on the packet data storage destination designated by the buffer management unit 112 and inputs the selected packet to the PDU generation unit 116. The PDU generation unit 116 converts the input packet into a PDU and inputs it to the transmission buffer 118.

[0078] The transmission buffer 118 waits independently for each destination (mobile station 200) from the input PDU based on the destination address input by the nota management unit 112 and the memory address of the corresponding queue. A queue is formed, and the status of each queue is notified to the buffer management unit 112.

The selector 120 extracts data from the queue designated by the scheduler 106 and inputs the data to the encoding / modulation unit 122 for the designated resource block. This resource block is allocated by the scheduler 106.

[0080] Scheduler 106 determines the priority determined based on the uplink control information (downlink reception channel state for each frequency block) and / or higher layer control signal of each mobile station 200 that has been notified. Based on the resource block to be allocated, the packet header information, and the status of each queue, an index (priority) for the allocation of the resource block of each user is obtained, and the allocation of the resource block is determined based on this index. Specifically, resource blocks and systems that divide the system bandwidth into consecutive frequency subcarrier blocks. One of the distributed resource blocks is allocated, which is composed of frequency subcarriers dispersed discretely within a system bandwidth and configured by dividing the resource block into a plurality of parts.

[0081] Further, as described above, the scheduler 106 adaptively changes the modulation scheme and the error correction coding rate according to the change in the propagation environment. Specifically, the combination of the MCS to be used, that is, the transmission data modulation scheme and error correction coding rate determined for each mobile station 200 is changed. Information indicating the combination of the changed transmission data modulation scheme and error correction coding rate is input to control signal generation section 126. The control signal generation unit 126 generates a control signal indicating a combination of the modulation scheme and error correction coding rate of the input transmission data, and transmits the control signal via the RF transmission unit 124. Further, the scheduler 106 designates a predetermined fixed number of transmissions.

[0082] The input data is encoded / modulated in the encoding / modulation section 122 based on the MCS to be used, and the encoded / modulated data is transmitted by the RF transmission section 124. The power is controlled and transmitted to each mobile station 200. For example, the MCS is changed at a period higher than the allocation period, and the transmission power is changed at the allocation period.

The mobile station 200 includes an RF receiving circuit 202, a subcarrier signal separation unit 204 connected to the RF reception circuit 202, a channel estimation unit 206 connected to the subcarrier signal separation unit 204, and a subcarrier signal. Downlink CQI measurement unit 208 connected to demultiplexing unit 204 and channel estimation unit 206, feedback data generation unit 210 connected to downlink CQI measurement unit 208, and encoding / modulation unit connected to feedback data generation unit 210 212, RF transmission circuit 214 connected to encoding / modulation section 212, allocation resource block information holding section 216 connected to subcarrier signal separation section 204, subcarrier signal separation section 204, and allocation resource block Demodulation unit 218 connected to information holding unit 216, decoding unit 220 connected to demodulation unit 218, CRC detection unit 222 connected to decoding unit 220, and IP packet connected to CRC detection unit 222 And a base portion 224.

The pilot channel transmitted from base station 100 is received by RF receiving circuit 202. RF receiving circuit 202 inputs the pilot channel to subcarrier signal separation section 204. Subcarrier signal separation section 204 separates the pilot channel into signals for each subcarrier, and separates the signal for each subcarrier for each subcarrier. And input to the downlink CQI measurement unit 208.

[0085] Channel estimation section 206 obtains a channel estimation value of each subcarrier using pilot symbols, and inputs the channel estimation value to downlink CQI measurement section 208. Downlink CQI measurement section 208 measures the average CQI of the transmission band of the pilot channel and inputs the measurement result to feedback data generation section 210. Based on the input CQI, feedback data generation section 210 generates feedback information (control information) indicating a downlink reception channel state to be fed back to base station 100, and inputs the feedback information to encoding / modulation section 212. . The encoding / modulation unit 212 performs encoding / modulation processing of feedback information, and the feedback information subjected to the encoding / modulation processing is transmitted to the base station 100 by the RF transmission circuit 214. For example, the radio resource for transmitting the downlink reception channel state is allocated immediately before the downward transmission.

Further, a transmission signal from base station 100 is received by RF reception circuit 202. The RF reception circuit 202 inputs the received signal to the subcarrier signal separation unit 204. Subcarrier signal separation section 204 separates the received signal into signals for each subcarrier, and inputs the separated signals for each subcarrier to demodulation section 218 for each subcarrier.

Demodulation section 218 demodulates the input signal for each subcarrier based on the allocation resource block information stored in allocation resource block information holding section 216, and demodulates the demodulated signal for each demodulated signal. The data is input to the decryption unit 220. Here, the allocated resource block information is included in a control channel notified by the base station 100, for example, an L1 / L2 control channel. The allocated resource block information includes, for example, MCS information.

Decoding section 220 decodes the input signal and inputs the decoded signal to CRC detection section 222. The CRC detection unit 222 detects a CRC on which UE-ID included in transmission data is superimposed, performs error detection, determines whether the transmission data is data for the own station, and If it is data, it is input to the IP packet restoration unit 224. The IP packet restoration unit 224 restores the input signal.

Next, base station 100 and mobile station 200 to which persistent scheduling is applied in the uplink will be described with reference to FIG. 10 and FIG.

[0090] The base station 100 includes an RF receiving circuit 102 and a demodulator connected to the RF receiving circuit 102 * decoding unit 1 04 and CQI measurement unit 128, demodulator 'determining unit 106 connected to decoding unit 104, scheduling unit 106 and CQI measuring unit 128 connected to priority allocation resource block determination · management unit 108 and scheduler 106 connected The control signal generator 126 and the RF transmitter 124 connected to the control signal generator 126 are provided.

[0091] Scheduler 106 allocates a pilot channel transmission band for measuring uplink reception channel state to mobile station 200 at a period longer than the data channel allocation period. Information indicating this transmission band allocation is input to the control signal generation unit 126 and transmitted via the RF transmission unit 124.

Each mobile station 200 transmits a reception channel state measurement signal to base station 100 using the allocated transmission band of the pilot channel. The reception channel state measurement signal is received by the RF receiving circuit 102, and the received reception channel state measurement pilot signal is input to the CQI measurement unit 128 to measure the reception quality, for example, CQI, and the reception channel state measurement. The information of the reception quality measured together with the signal for use is input to the determination / management unit 108 of the priority allocation resource block. Information indicating the presence / absence of transmission data in the mobile station 200 is received by the RF reception circuit 102 and is input to the priority allocation resource block determination / management unit 108 via the CQI measurement unit 128.

Further, the presence / absence of transmission data in mobile station 200 may be notified by a control signal of an upper layer. In this case, the upper layer control signal is input to the priority allocation resource block determination / management unit 108.

[0094] Determination / priority allocation resource block determination / management section 108 performs priority based on reception quality of a pilot signal for reception channel state measurement, higher layer control signal, and information indicating presence / absence of transmission data in mobile station 200. The resource block to be assigned to the resource block, that is, the resource block to which the persistent scheduling is applied, is determined and input to the scheduler 106.

[0095] The scheduler 106 determines a priority allocation resource block. The scheduler 106 determines the allocation of the resource block based on the priority allocation resource block input by the management unit 108, and determines the allocation information of the determined resource block. Input to the control signal generator 126. The control signal generation unit 126 generates resource blocks determined by the scheduler 106. Based on the allocation information, that is, the transmission bandwidth of the data channel, the allocation information of the uplink transmission band is generated and input to the RF transmission unit 124. The RF transmitter 124 transmits the control signal input by the control signal generator 126 to each mobile station. As a result, the base station 100 notifies the mobile station 200 of uplink transmission allocation information.

[0096] For example, radio resources for uplink data transmission are allocated after downlink data transmission. Here, scheduler 106 determines a combination of the transmission data modulation scheme and error correction coding rate for each mobile station in a cycle longer than the allocation cycle, and determines the determined transmission data modulation scheme and error correction coding rate. The combination of these is reported as control information.

Further, transmission data from mobile station 200 is received by RF reception circuit 102 and input to demodulation / decoding section 104. Demodulation'decoding processing section 104 performs demodulation processing and decoding processing of the input transmission data. Further, the demodulation / decoding section 104 notifies the scheduler of the uplink CQI for each resource block of each user terminal.

[0098] Scheduler 106 determines resource block reallocation based on the CQI input by demodulation and decoding section 104 at a predetermined allocation cycle, and uses the determined resource block allocation information as a control signal generation section Enter in 126. The control signal generation unit 126 generates uplink transmission band allocation information based on the resource block allocation information determined by the scheduler 106 and inputs it to the RF transmission unit 124. The RF transmission unit 124 transmits the control signal input by the control signal generation unit 126 to each mobile station. For example, the result of this reallocation is notified at the same time as downlink data transmission.

[0099] Mobile station 200 is connected to header information acquisition section 226, PDU generation section 228 connected to header information acquisition section 226, transmission buffer 230 connected to PDU generation section 228, and transmission buffer 230 The buffer management unit 234, the encoding / modulation unit 232, the feedback data generation unit 236 connected to the buffer management unit 234, the encoding / modulation unit 238 connected to the feedback data generation unit 236, and the pilot signal generation Unit 240, and RF transmitter circuit 242 connected to encoding / modulating units 232 and 238 and pilot signal generating unit 240.

[0100] Pilot signal generating section 240 is configured to transmit an uplink signal based on information indicating a transmission band of a pilot channel for measuring an uplink reception channel state notified from base station 100. A pilot signal for measuring the reception channel state of the link is generated and transmitted via the RF transmission circuit 242.

[0101] The IP packet from the upper layer is input to the header information acquisition unit 226. The header information acquisition unit 226 acquires packet header information such as a destination address from the received IP packet, notifies the acquired packet header information to the buffer management unit 234, and inputs the IP packet to the PDU generation unit 228.

[0102] The PDU generation unit 228 converts the input packet into a PDU and inputs the packet to the transmission buffer 230. The transmission buffer 230 forms a queue for the destination (base station 100) from the input PDU based on the destination address input by the nota management unit 112 and the memory address of the corresponding queue, and waits for it. The buffer status is notified to the buffer manager 234.

[0103] Information indicating the allocated data channel transmission band is notified from the base station 100 to the nota management unit 234. Also, the transmission data modulation scheme and error correction coding rate combination determined for each mobile station is notified.

[0104] The transmission buffer 230 extracts data from the queue based on the uplink transmission allocation information specified by the nota management unit 234, that is, information indicating the allocated data channel transmission band, and encodes and modulates the data. Input to part 232 The encoding / modulation unit 232 performs encoding / modulation processing based on the combination of the transmission data modulation scheme and error correction coding rate determined for each mobile station, and inputs the result to the RF transmission circuit 242. In the RF transmission circuit 242, transmission power control is performed on transmission data and transmitted.

[0105] The noffer management unit 234 inputs the destination address and the memory address of the queue corresponding to the address to the transmission buffer 230. Further, the buffer management unit 234 notifies the feedback data generation unit 236 of the packet header information and the queue status notified from the transmission buffer 230. The feedback data generation unit 236 generates feedback information indicating the presence / absence of transmission data based on the input queue state, and inputs the feedback information to the encoding / modulation unit 238. The encoding / modulation unit 238 transmits the input feedback information to the base station 100 via the RF transmission circuit 242.

[0106] For convenience of explanation, the present invention has been described in several embodiments. However, the classification of each embodiment is not essential to the present invention, and two or more embodiments may be used as necessary. invention Forces explained using specific numerical examples to promote understanding Unless otherwise noted, these numerical values are merely examples, and any appropriate value may be used.

[0107] Although the present invention has been described above with reference to specific embodiments, each embodiment is merely an example, and those skilled in the art will appreciate various variations, modifications, alternatives, and substitutions. You will understand. For convenience of explanation, the device according to the embodiment of the present invention has been described using a functional block diagram. However, such a device may be realized by hardware, software, or a combination thereof. The present invention is not limited to the above-described embodiments, and includes various modifications, modifications, alternatives, substitutions and the like without departing from the spirit of the present invention.

[0108] This international application claims priority based on Japanese Patent Application No. 2006-225927 filed on August 22, 2006, and the entire contents of 2006-225927 are incorporated herein by reference. .

Industrial applicability

[0109] The base station and mobile station that are effective in the present invention can be applied to a radio communication system.

Claims

The scope of the claims

[1] A resource block that divides the system bandwidth into contiguous frequency subcarrier blocks and a frequency subcarrier that is discretely distributed within the system bandwidth. The resource block is divided into multiple parts. Assign one of the type resource blocks to each mobile station,

A base station comprising:

[2] In the base station according to claim 1:

The base station characterized in that the scheduling means allocates different resource blocks or distributed resource blocks for each allocation period.

[3] In the base station according to claim 1:

The base station characterized in that the scheduling means allocates a predetermined number of transmission slots within the allocation period.

[4] In the base station according to claim 1:

Based on the downlink reception channel state, a combination of a transmission data modulation scheme and an error correction coding rate is determined for each mobile station in a period longer than the allocation period, and the determined transmission data modulation scheme and error correction are determined. Coding and modulation processing means for performing coding processing and modulation processing based on a combination of coding rates;

Transmission power control means for controlling transmission power in the allocation period;

A base station comprising:

[5] In the base station according to claim 1:

The base station characterized in that, when there is no data for a mobile station to which a resource block or a distributed resource block is allocated, the scheduling means allocates the resource block or the distributed frequency block to another mobile station.

[6] Pilot channel transmission band that allocates the pilot channel transmission band for measuring the uplink reception channel state with a period longer than the data channel allocation period Area allocation means;

A data channel transmission band allocating means for allocating a resource block obtained by dividing the system bandwidth into continuous frequency subcarrier blocks to each mobile station as a data channel transmission band;

The data channel transmission band allocating means determines a data channel transmission band allocation based on the pilot channel reception quality! /

[7] Pilot signal generating means for generating the pilot channel with a period longer than the data channel allocation period for the base station using the frequency band allocated by the base station;

A mobile station comprising:

[8] In the mobile station according to claim 7:

The mobile station characterized in that the transmission data allocating means switches resource blocks allocated for each transmission slot.

[9] In the mobile station according to claim 7:

The transmission data allocating means allocates a different resource block for each allocation period.

[10] In the mobile station of claim 7:

The transmission data allocating means allocates a predetermined number of transmission slots within the allocation period.

[11] Claim 7! /, Or any of the mobile stations listed in Section 1! /

Based on the uplink reception channel condition, the transmission data modulation method and And the error correction coding rate combination are determined in a cycle longer than the allocation cycle, the determined transmission data modulation method and error correction coding rate combination are notified, and the notified transmission data modulation method and error correction are notified. Coding / modulation processing means for performing coding processing and modulation processing based on the combination of coding rates;

A mobile station comprising:

In the mobile station according to claim 7:

A notification means for notifying the base station to which the resource block has been assigned information indicating the presence or absence of transmission data;

A mobile station comprising: